Detachable blade scalpels



M y 7, 1955 w. E. STEELE DETACHABLE BLADE SCALPELS Filed May 12, 1952 25. ME y m5 M m 56 [4 BY United States Patent 0 DETACHABLE BLADE SCALPELSWilliam E. Steele, Seattle, Wash.

x Application May 12, 1952, Serial No. 287,313

7 Claims. (Cl. 39-639) .This invention relates to improvements indetachable blade scalpels generally of the type disclosed in my UnitedStates Patent No. 2,454,353 of November 23, 1948 entitled DetachableBlade Scalpel. More particularly, the present invention concerns ascalpel handle arrangement which is adapted to receive and to retainmore securely and rigidly than heretofore certain types of commerciallyavailable scalpel blades and blades of equivalent construction. Arelated object is a detachable blade scalpel also constructed andarranged to facilitate and expedite the installation and removal ofblades from the handle. The invntion is herein illustratively describedby reference to the presently preferred form thereof as applied to a particular commercially available type of scalpel blade, but it will beunderstood that the invention extends to equivalent forms within theprinciples disclosed herein and obviously is not confinedto the.illustrative details.

In addition to the requirement of rigid full support for the scalpelblade, it is important that the handle elements releasably engaged bythe blade prevent any appreciable or noticeable displacement betweenblade and handle in any direction during all types of cutting operationsperformed with the scalpel. In addition it is essential that blades bequickly exchangeable if one of difierent shape is desired for theoperation, and that there be no tendency for the blade to bind on thehandle or be dangerous to remove or install with rubber gloves worn bythe surgical assistant. Certain commercially available surgicalscalpel-blades for detachable blade scalpels have experienced widespreaduse and are of the highest quality suitable for numerous applications inthe various shapes and sizes in which they are produced. However, theavailable ha'ndlearrangements for mounting these blades when measuredagainst the above-mentioned requirements and others for a perfecteddetachable blade scalpel have fallen short of their full purpose, and itis the general object of the present invention to provide an improvedhandle arrangement.

V The particular commercial type of blade upon which the disclosure ofthis invention is based herein comprises a fiat steel body with orwithout a reinforcing rib along the back edge and with an elongatedaperture or slot extending lengthwise of the blade generallyintermediate its ends and opposite side edges, such aperture or slotbeing widest at its end nearest the butt of the blade and undergoing oneor more successive reductions in width toward the cutting end thereof.Such stepped portions, at least beyond the first step, areinconsequential.

Described in brief terms, the improved detachable blade scapel handlehaving the advantages mentioned for a blade of the foregoing type,comprises a shank and a tongue projecting beyond one end thereof. Thetongue has a blade-supporting side face comprising a substantiallyflatblade-engaging outer portion and a raised bladee'ngaging root portion. Aheaded pin projects laterally from the outer portion of the tongue faceand a second pin projects laterally adjacent to the raised root portionthereof. The apertured blade slips over the headed pin ice with theblade disposed transversely to the tongue and is then rotated about thepins axis into general alignment with the handle. A rib extending alongone side edge of the tongue and of a height, perpendicular to the tongueface, which progressively increases towards the tongue root, deflectsthe butt end of the blade up and over the second pin during swinging ofthe blade toward alignment with the handle. Upon reaching suchalignment, the butt end of the blade snaps resiliently against theraised root portion of the tongue and the second pin enters theregistering blade aperture to lock the blade in position. The blade isthen held under stress by pressure of the underside of the first pinshead causing the blade to bend as a result of its contact with thenon-coplanar portions of the tongue face.

These and other features, objects and advantages of the presentinvention will become more fully evident from the following descriptionof the preferred form thereof as illustrated in the accompanyingdrawings.

Figure l is a perspective view of the scapel handle with its major shankportion broken away for convenience of illustration.

Figure 2 is a similar perspective view with the scalpel blade secured inplace on the handle.

Figure 3 is a similar perspective view with the scalpel blade laidtransversely across the handles tongue and the headed pin on the tonguepassed through the blade aperture in the initial step of the procedurefor mounting the blade.

Figure 4 is a side view of the scalpel blade and handle combination inwhich the blades position as shown by solid lines corresponds to that inFigure 3 and by broken lines corresponds to the installed positionillustrated in Figure 2.

Figure 5 is a perspective View similar to Figure 3 but in which theblade is swung about the headed pin part way toward alignment with thehandle as required for securement thereto.

Figure 6 is an edge view of the handle, at enlarged scale, parts beingbroken away, showing the blade postioned relative to the handle as inFigure 5, the sloped rib deflecting the swinging blade automatically forclearance over the second pin.

Figure 7 is a cross section of the scalpel taken on line 7-7 in Figure2.

As illustrated in the various figures, the scalpel handle comprises theshank 10 and the tongue 12 projecting beyond one end thereof. The tonguehas a blade-engaging side face made up of a generally fiat outer portion14 and a raised or offset root portion 16 progressively curved outwardlyof the general plane of such outer portion. The specific curvature inlongitudinal cross section, for instance, of this blade-stressing faceof the tongue is not critical, as will become evident. It may in fact beformed by an abrupt rise in the face of the tongue or by a more gentlecurve as indicated in the example. The root end of this tongue face ismet by a perpendicular shoulder 18 on the adjoiningend of shank 10,which shoulder in the illustrated case is inclined diagonally to thehandles longitudinal axis insubstantial conformity to the angularity ofthe butt end of the particular blade chosen for purposes ofillustration. This shoulder actually has some setback from the very endof the shank 1!) and extends across the width thereof from locationsnear its opposite edges so as to form the end wall of a three-sidedblade-receiving pocket which opens both laterally and endwise of thehandle. The opposite sides of this pocket comprise the shoulder 20extending a short distance along one edge of the tongue, and the rootend portion of the rib 22 which extends along the opposite side edge ofthe tongue over substantially its full length. i

The upper side of the rib 22 curves upwardly in progressive mannertoward the 'root end thereof and continues into a similarly sloped shanksurface 22:: adjoining the shoulder 18 for a purpose which will laterbecome evident. A heightening in this rib near its outer end provides arelatively wide finger rest 22b for cutting pressure application by thesurgeons index finger and afi'ords transverse support to the back edgeof the installed blade during cutting. A groove 2 (Figure 7) extendinglengthwise along the base of the rib 22 over 'its full length isprovided to receive one flange of a reinforcing rib 34 on the back edgeof the type of blade herein illustrated. The tongue is indented ornarrowed at 26 near its root to enable grasping the blades shank forlifting of the blade shank in the course of removing it from the handle;

A headed pin 28 projecting laterally from a generally intermediatelocation on the outer portion 14 of tongue 12 has a round shank 28a(Figure 5) flattened on opposite sides which face endwise of the tongue.The'pin head 28b, of elongated form, extends transversely of the tongue.A second pin 38, preferably unheaded, and of the same a diameter as theshank 28a of pin 28 in the illustrated case projects laterally from agenerally intermediate location on the upwardly curving root portion160i tongue 12. Preferably the two pins occupy positions of approximatealignment lengthwise of the tongue. Pin 3% and the shank of pin 28 areboth preferably of a projecting height very slightly'in excess of theblades thickness.

Asillustrated, the scalpelblade 32 has a double reinforcing rib 34 alongits back edge, a cutting edge 36, shown extending diagonally to a point,an unsharpened shank edge 38 located opposite the back edge 34, and aninclined butt edge 40 previously mentioned. Generally intermediate itsseveral edges the body of blade 32 has an elongated aperture or slot 42extending lengthwise therein. This slot comprises a root section 42a, anintermediate section 42b and a tip section 42c, each being ofuniform'width and, in the order named, being somewhat wider thanitssuccessor. The presence of aperture sections 42b and 42c, ofsignificance in previous usages of this particular commercial type ofblade, is unessential for present illustrative purposes, however,wherein the root section 42a alone of the blade aperture comes intoplay, and the length of even this portion is not critical.

The width 'of this aperture root section 42a is very slightly inexcessof the diameter of pins 28 and 39. Its length is such that itslips over the two pins with slight but inappreciable clearance at itsremote ends and sides,

so thatin the blades installed position (Figure 2, Figure 4-dotted) oneend edge of the aperture bears against the side of one pin to preventappreciable endwise shifting or free play of the blade in one directionrelative to the handle, -whereas the same is true of the opposite endedge of such aperture and the other pin, with respect to relativeshifting of the blade in the opposite Being of crucible steel orcomparable The blade is then swung clockwise about pin 28 through I theposition of Figure 5, toward "that of Figure 2. As the blade swings inthis manner its butt portion slides on the upwardly curved face of rib22 and contiguous shank surface 22a. The leading edge of theprogressively deflected blade is thereby automatically raised abovethetop of pin 59 (Figure 6) so that it clears thepin' as its swingingmovement progresses through the position of Figures 5 and 6. While thebutt edge of the blade is being deflected progressively upward by thecam action of rib 22- and surface 22a, the head 28b of pin 28 holdsdown'the body of the blade in face-to-face freely sliding contact withthe tongue. Thus very little effort is required to swing theprogressively bent blade into align-. ment with the handle.

When the blade is swung into such alignment its butt end finally dropsoil the rim of shoulder 18 and snaps down resiliently to a seat in thepocket previously described. This it does at a position of the blade inwhich the pin 30 automatically slips quite snugly, though freely, intothe root end of aperture 42 of the descending blade, assuming, ofcourse, that the shank 28a of the other pin is then being pressed by theopposite end edge of 'aperture section 42a. The blade is then securedfirmly in place on the handle. Of course, if the pin 28 lies in anintermediate position lengthwise of aperture section 42a as the blade isswung into alignment'with the handle, pin 39 will prevent the blade buttfrom snapping to its seat. In that event it is an easy matter tocomplete the mounting operation by sliding the blade endwise of thehandle until it does snap down over the pin 30.

The blades snug engagement with the face of tongue 12 and with pins 28and 30, together with the augmented support afforded to it by adjoiningrib and shoulder Sllr faces insures a minimum of free play or loosenessin the connection and also a maximum of support to the thin bladeagainst undue bending under operating pressure. Moreover, the continuedbending stress residing in the resilient blade caused by the/undersideof pin head 28b holding the blade down against the curved face of thetongue 12 further adds to the tightness of the securement. and reducesthe possibilities of accidental dislodgement of the blades aperture fromretaining pin 30. A very important feature of the simple and readilymanufactured engaging blade aperture edges to prevent shifting of theblade in any sense in its own plane. p

In order to remove the blade, its shank is simply grasped at thelocation of the tongue indentation 26, lifted clear of pin 30, and thenswung counterclockwise to the position of Figure 3 or 4. The blade isthen simply slipped off pin 28 free of the handle.

In the structure described above, it has been assumed that the shouldersformed by the step from slot portion.

42a to slot portion 42b engaging the shank 28a of the. headed pin 28would hold the blade against rearward movement and the engagement of therearward end of slot portion 420 with pin 30 would hold the bladeagainst forward movement. While the latter engagement is'principallyrelied upon to prevent forward movement of the blade, engagement of thetoe of the blades butt end with shoulder 20 would assist somewhat inthus holding the blade. 7

Various alternatives for restraining rearward movement of the blade arepossible in addition to or instead of the movement. For that reason itis not necessary that the blade shoulders between such blade slotportions 'actually'i engage the pin shank, although it is desirable tohave pins 28 and 30 separated a considerable distance.

Also, while engagement of theedges of slot portibrf 42a with. the sidesof pin shank 28a and pin 30 hold the blade against lateral and swingingmovement, it 'is not necessary that the sides of pin 30'engage the sidesof such slot portion with the handle socket for the blade, butt shown inFig. 2. Rotation of the blade in a clockwise dithe blade root end withshoulder20. Rotation of thei' blade in a counterclockwise directionabout pin 28 is pre-' vented by engagement of the back of the blade atits root 7 end with rib 22. As long as the rearward face of'piii' 30engages the rearward end of blade'slot 42, therefore;

the blade will be held satisfactorily in place against swinging byengagement of the blade edge with shoulders on the handle as discussed.If the blade aperture or slot does fit the pin 30 snugly, however,laterally as well as lengthwise of the handle, provision of such bladeedge engaging shoulders is not necessary.

I claim as my invention:

1. A detachable blade scalpel comprising an elongated blade havingtherein an elongated slot extending lengthwise of the blade, and ahandle including a shank, a tongue projecting from one end of said shankand having a blade-supporting side, a first pin projecting laterallyfrom said tongues blade-supporting side at a location spaced from saidshank, having a head of an extent transversely of said tongue greaterthan its extent lengthwise of said tongue and greater than the width ofsaid blade slot but less than the length of such blade slot, the extentof said head lengthwise of the tongue not exceeding the maximum width ofsaid blade slot, for passage of said head through said blade slot onlywhen the length of said blade extends transversely of said tongue, andsaid first pin having a stem of an extent both lengthwise of said tongueand transversely of said tongue not exceeding the maximum width of saidblade slot, to enable said blade, after passing over said pin head, tobe swung beneath said pin head into substantial alignment with saidtongue, and an unheaded pin projecting laterally from said tonguesblade-supporting side at a location between said first pin and saidshank, said unheaded pin being of a size to fit in said elongated bladeslot when the blade has been swung to dispose its length in alignmentwith said tongue, said handle having a rib extending along one edge ofthe blade-supporting side of the tongue, the height of said rib abovesuch tongue side tapering away from the shank for engagement by theblade engaged beneath the head of the first pin to bend the bladeprogressively as it is swung toward alignment with the tongue, forpassage of the blade over the top of the unheaded pin.

2. A detachable blade scalpel handle comprising a shank, a tongueprojecting lengthwise of the handle from one end of said shank, saidtongue having a blade-supporting side and a blade-backing rib projectingfrom said side and extending lengthwise of said tongue substantiallyfrom said shank to the projecting end of said tongue, a first pinprojecting laterally from said tongues bladesupporting side at alocation spaced from said shank, having a head of an extent transverselyof said tongue greater than its extent lengthwise of said tongue and astem of an extent lengthwise of said tongue not exceeding its extenttransversely of said tongue, and an unheaded pin projecting laterallyfrom said tongues bladesupporting side adjacent to said rib, said pinsbeing engageable with a scalpel blade for holding the same to the handlewith the back edge of the blade abutted to said rib.

3. A detachable blade scalpel handle comprising a shank, a tongueprojecting from one end of said shank and having a blade-supportingside, a first pin projecting laterally from said tonguesblade-supporting side at a location spaced from said shank, having ahead of an extent transversely of said tongue greater than its extentlengthwise of said tongue and a stem of an extent lengthwise of saidtongue not exceeding its extent transversely of said tongue, an unheadedpin projecting laterally from said tongues blade-supporting side at alocation between said first pin and said shank, and a rib between saidheaded pin and said shank, extending lengthwise of said tongue, spacedlaterally of said tongue from said unheaded pin, its height above suchtongue side tapering away from shank, and having a maximum height atleast substantially as great as the height of said unheaded pin.

4. The detachable blade scalpel handle defined in claim 2, wherein thetongue projects lengthwise from the shank materially beyond the firstpin, and wherein the rib is heightened between such pin and theprojecting end of the tongue, such heightened rib portion constituting afinger rest in addition to a backing for a scalpel blade secured to thehandle.

5. A detachable blade scalpel handle comprising a shank, a tongueprojecting lengthwise from one end of said shank and having ablade-supporting side, a headed pin projecting from said tongue side ata longitudinally intermediate location thereon engageable with anapertured scalpel blade to hold such blade in contact with said tongueside, a blade-backing rib at least substantially as high as the lengthof said pin between its head and said tongue, projecting laterally fromsaid tongue side and extending lengthwise of said tongue along onelongitudinal edge thereof between said headed pin and the projecting endof said tongue to afford a blade stop and finger rest, and meansprojecting laterally from said tongue side between said shank and saidheaded pin, said latter means being engageable with a root end portionof a scalpel blade held by said pin in contact with said tongue side toprevent swinging of the blades root end about said pin.

6. A detachable blade scalpel comprising, in combination, a scalpelhandle including a shank, a tongue projecting lengthwise from one end ofsaid shank and havin a blade supporting side, a rib projecting laterallyfrom said side and extending lengthwise of said tongue along onelongitudinal edge thereof, the projecting height of said rib above saidtongue side being gradually and progressively increased towards saidshank from a location generally intermediate the ends of said rib, andthe height of said rib being materially increased substantiallythroughout that portion of the length thereof extending between saidlocation and the projecting end of said tongue to aiford a blade stopand finger rest, a headed pin projecting from said tongue side at alongitudinally intermediate location thereon, the head of said pinhaving an extent transversely of said tongue greater than its exentlengthwise of said tongue, an elongated scalpel blade having anelongated aperture therein extending lengthwise of said blade and havinga length greater than the length of said pins head and a width less thanthe length of said pins head, but slightly greater than the width ofsuch head, whereby said blade may be passed over said pins head andpressed into contact with said tongue side with said blade extendinggenerally transversely to said tongue, and an unheaded pin projectingfrom the tongue side at a location thereon between the headed pin andthe shank, said blade, pressed against said tongue side with itsaperture engaged with said headed pin, being swingable about the axis ofsuch pin, held by and beneath the head thereof, toward alignment withsaid tongue accompanied by progressive deflection of the butt endportion of said blade away from said tongue side by riding up thegradually increased height of said rib until such alignment is reached,permitting such blade butt portion to snap down into contact with saidtongue side and engage its aperture with said unheaded pin to preventfurther swinging of said blade.

7. A detachable blade scalpel comprising a blade including a sharpcutting edge and a blunt longitudinal opposite edge, said blade havingan elongated aperture therein extending lengthwise thereof intermediatethe ends of such blade, and a scalpel handle cooperable with said bladecomprising a shank, a tongue projecting lengthwise of the handle fromone end of said shank, said tongue having a blade-supporting side and ablade-backing rib projecting laterally from said side and extendinglengthwise of said tongue substantially from said shank to theprojecting end of said tongue, a pin projecting laterally from saidtongues blade-supporting side at a location spaced from said shank, saidpin having a head of an extent transversely of said tongue greater thanits extent lengthwise of said tongue and a stem of an extent lengthwiseof said tongue not exceeding its extent transversely stop meansprojecting laterally from said tongues bladesupporting side at alocation thereon between said headed pin and said shank, said stop meansbeing engageable with a cooperable portion of said blade to arrestswinging of said blade about said headed pin when said blade is swungfrom its transverse position toward and into alignment with said tongue,said blade-backing rib being spaced from said stop means transversely ofsaid tongue to contact the blunt edge of said blade substantiallycontinuously along the length of said rib with said blade thuspositioned in alignment with said tongue.

References Cited in the file of this patent UNITED STATES PATENTS WaughSept. 30, 1941 Steele Nov. 23, 1948

